Covalent Organic Framework Coupled with Atomically Precise Copper Nanoclusters for Efficient Tandem Electroreduction Reaction of CO<sub>2</sub>
Song Zheng, Duan‐Hui Si, Hui Guo, Qiu‐Jin Wu, Hong-Jing Zhu, Yuan‐Biao Huang, Rong Cao
Abstract
The electrocatalytic reduction of CO 2 (CO 2 RR) presents a viable approach to reduce CO 2 emissions and generate valuable chemicals. However, selectivity toward highly valuable C 2+ products is still insufficient for practical applications. Herein, we propose an efficient tandem catalytic strategy to polish up the performance of C 2+ products via adjacent distinct catalytic sites. The tandem electrocatalyst Cu/NiPc-COF is constructed by uniformly dispersing atomically precise copper nanoclusters [Cu 32 (PET) 24 H 8 Cl 2 ](PPh 4 ) 2 (PET = 2-phenylethanethiolate), denoted as Cu 32 NCs, on the two-dimensionally conductive Ni-phthalocyanine-based covalent organic framework (NiPc-COF). A high selectivity of 57.1% for C 2+ products (C 2 H 4, CH 3 COOH, and C 2 H 5 OH) and a total current density of 353.3 mA cm –2 is reached at −1.6 V in aqueous electrolyte, which surpasses the corresponding Cu 32 NCs (FE C 2+ = 24.4%, j total = 250.1 mA cm –2, −1.6 V) and some other electrocatalysts. Operando experiments and DFT calculations show that locally high *CO concentrations from NiPc-COF sites cause a massive *CO spillover to Cu 32 NCs. This enriches *CO coverage, boosting the selectivity of C 2+ . The work provides an effective approach for designing tandem electrocatalysts that achieve high selectivity to C 2+ .